1. Field
The present invention relates to an information processing apparatus having an antitheft function and an antitheft method for the information processing apparatus.
2. Description of the Related Art
Rapid progress in technologies of reduction in size and weight saving for information processing apparatuses has been notable in recent years. Particularly, in a personal computer field, portable and highly functional notebook personal computers with higher performance have been in widespread use. Notebook personal computers are generally used not only during business trips or outside offices but also in offices or at home, in place of conventional stationary desktop personal computers.
Since compact information processing apparatuses typified by the notebook personal computers can easily be carried, various antitheft measures have been devised.
For example, Japanese Patent Application Publication (KOKAI) No. 9-198576 discloses a compact antitheft device mountable in an information processing apparatus. Such a compact antitheft device includes a vibration sensor to determine whether the information processing apparatus is carried based on a vibration period or the like. If it is determined that the information processing apparatus is carried, an alarm sound is generated by a built-in speaker. The alarm sound continues to be generated unless authentication by using a password known only to a legal owner succeeds.
Japanese Patent Application Publication (KOKAI) No. 2000-155876 discloses an information processing apparatus having an antitheft function. The information processing apparatus determines whether it is carried based on information in a distance sensor, an illumination sensor, or a gyro-sensor included in the information processing apparatus. If the information processing apparatus determines that it is not carried, the need for power-on password authentication or password authentication for decoding is eliminated, thus increasing the usability of a user.
If the information processing apparatus determines that it is carried, the information processing apparatus not only generates an alarm, but also requests the carrier to perform the power-on password authentication or the password authentication for decoding. If the authentication fails, the information processing apparatus stops a startup sequence to prevent the carrier from using the information processing apparatus.
Japanese Patent Application Publication (KOKAI) No. 2002-99347 discloses an information processing apparatus having an antitheft function, which can be realized in lower power consumption and at a lower cost. The information processing apparatus detects that it is carried by using a switch provided on the bottom of the information processing apparatus to generate an alarm by a sound source dedicated to alarm generation. A legal owner can stop the alarm by inputting an alarm-clear password.
When the information processing apparatus is separated from the antitheft device (for example, Japanese Patent Application Publication (KOKAI) No. 9-198576), the antitheft device can advantageously be mounted in various information processing apparatuses.
However, in order to prevent an illegal carrier from easily detaching the antitheft device, the antitheft device must be mounted in the information processing apparatus and, therefore, it is not easy to mount the antitheft device. In addition, it is hard to access the antitheft device mounted in the information processing apparatus when a legal owner is to input a password for clearing the alarm.
In contrast, in Patent Documents 2 and 3, the antitheft function is incorporated in the information processing apparatus.
Generally, the antitheft function for the information processing apparatus is required when a legal owner is absent and the main power supply of the information processing apparatus is turned off. In many information processing apparatuses, a function for determining whether a main-power-supply switch is turned on or a clock function is enabled even when the main power supply is turned off. However, the power consumption in these functions is low, and the power supply system with the main power supply being turned off is often structured on the assumption of the low power consumption. Hence, the information processing apparatus having the antitheft function realized in low power consumption is required even when the antitheft function is incorporated in the information processing apparatus.
The invention disclosed in the Japanese Patent Application Publication (KOKAI) No. 2000-155876 is disadvantageous in the power consumption, whereas the antitheft function realized in low power consumption is disclosed in Japanese Patent Application Publication (KOKAI) No. 2002-99347.
However, in known inventions already disclosed, the functions of the information processing apparatuses are separated from the antitheft function even when the antitheft function is incorporated in the information processing apparatuses. Accordingly, a method of clearing an alarm by inputting an alarm-clear password when a legal owner erroneously generates the alarm is different from a method of inputting the power-on password for activating the information processing apparatus. Such information processing apparatuses are inconvenient to the legal owner in usability.
In addition, since the functions of the information processing apparatuses are separated from the antitheft function, only the antitheft function is enabled when the information processing apparatuses are carried. Specifically, only limited antitheft means, such as an alarm sound, can be adopted.
It is anticipated that, in order to stop any generated alarm, an illegal carrier turns off the power supply switch, removes the battery, or lowers the sound volume of the alarm. Satisfactory countermeasures against such actions have not been disclosed yet.